With the advent of the Internet, communication by electronic mail or email has become common practice. The Internet is also extensively used to conduct business transactions, and such transactions often require the exchange of confidential information such as credit card details, bank account details, passwords, personal details, and the like. Persons of devious intent often use so-called “spoofed” email messages in order to induce a recipient to furnish confidential information. The perpetrator then uses the confidential information in a fraudulent manner such as, for example, to bid on items, or post fictitious items, on an Internet auction web site.
An email message typically includes a header visible to a recipient that shows who purportedly sent the email (“FROM:” field), to whom the email was sent (“TO:” field), the subject matter of the email (“SUBJECT:” field) and the date and time of sending the email (“DATE:” field). In order to mislead the recipient or victim of the actual source of the email, a person launching a spoof attack typically alters the (“FROM:” field) to reflect a known or reliable source. Thus, when the recipient receives the spoofed email, the “FROM:” field may show an email address that is totally unrelated to the sender. If the recipient were to reply to the email, the sender may then obtain confidential information which the victim believes is being sent to a legitimate source.